Yarn package



Jan; 31, 19 7 L, a 8mm 3,301,506

YARN PACKAGE Filed April 29, 1964 INVENTOR LEWIS BROWN BAGBY BY @{C w ATTORNEY United States Patent 3,301,506 YARN PACKAGE Lewis Brown llagby, Waynesboro, Va., assignor. to E. I. du Pont de Nemonrs and Company, WilmingtomDeL, a corporation of Delaware Filed Apr. 29, 1964, Ser. No. 363,477 1 Claim. (Cl. 242-466) This invention relates to core structures on which materials of various kinds can be Wound, and in particular to a unitary core structure which can when desired be separated into a plurality of individual elements.

In the manufacture of many commodities, for example, ribbons, tapes, threads, yarns, wire, and films, it is frequently desirable for reasons of convenience and economy to wind a plurality of packages simultaneously. The number of winding machines required can be minimized and the design and structure of the individual winding machines can be simplified if a plurality of wound packages can be produced in spaced relationship on a unit core structure which can later be separated to provide individual packages of the wound materials.

Various means have been tried to provide a unitary but separable core structure (see British Patent 804,045 November 5, 1958, and British Patent 619,038 March 3, 1949). For example, it has been proposed to score or cut a tube to provide deep circumferential grooves at the points where separation will later be desired. For wound paper cores, it has been proposed to slit the paper sheet for a major portion of its length before winding so that after winding only a few inner layers of paper remain intact at the desired separation points. It has also been proposed to wrap a number of individual core elements in a paper sleeve or envelope which can later readily be fractured.

For many uses, these solutions of the problem are satisfactory, especially when the wound packages are of small size and light weight. However, when large, heavy packages are to be wound, each of these proposed methods may introduce disadvantages. For example, when the unitary tube is weakened by deep circumferential grooves, achieved by cutting or scoring or by winding pre-slit paper, the unitary'core may have inadequate strength to support large, heavy packages and may collapse or buckle because of movement during the winding operation itself or during shipping or use. In addition, when the unitary core itself is made of paper or when a number of individual cores are wrapped with a paper sleeve or envelope, jagged edges of paper may be created at both ends of the individual packages when the unitary core is separated into its component elements. The jagged edges of paper are undesirable in many applications. For example, damage to the yarn may result during the over end take-off of low-denier, low-twist textile yarns due to abrasion caused by the jagged edges. Also, in the winding of fine filamentary materials such as wire or textile yarns, the

presence of deep circumferential grooves along the surface of the unitary core structure is undesirable, because the grooves can entrap the filamentary materials with consequent breakage of the material and interruption of the winding operation. These difficulties are especially likely to occur at start-up of winding before package formation is firmly established.

In accordance with the present invention, at least two cylindrical elements are fixed in abutting end-to-end relationship by a high shear but low tensile strength adhesive resulting in a tubular package core that is divisible into the individual elements by slight tensile force.

The unitary core structures of the invention have strength and stability, adequate to withstand the mechanical strains of winding at high speeds and yet are readily pulled apart into the individual core components when 3,301,506 Patented Jan. 31, 1967 r6 ce desired. Further, the unitary core structure of this invention is readily manufactured by means that are simpler and more economical than those previously proposed.

The yarn package of the invention constitutes a unitary tubular core composed of at least two rigidly secured but readily separable cylindrical core elements axially aligned and arranged in abutting end-to-end relationship, with each core element bearing a separate winding of textile yarn. The core elements are joined by a latex based adhesive, as will be described below, that is located at spaced areas within the abutting end surface areas of the core elements. Due to the high shear strength and low tensile strength characteristics of the adhesive, the unitary core structures can withstand the strains of winding and are readily separable by slight tensile force. In this manner, the yarn may be simultaneously unwound from each core or the separated core elements and windings may be employed as individual yarn packages. Each. core element has end and central sections. The central section is of uniform radius along its length and constitutes the yarn winding support. Each end section has a radius that. does not exceed that of the central section to permit overend take off while avoiding yarn abrasion.

The inventionwill be readily understood by reference to the drawings, wherein:

FIGURE 1 is a perspective view of a unitary core structure of this invention;

FIGURE 2 is a perspective view of an individual core element;

FIGURE 3 is a perspective view of the individual core element of FIGURE 2; and

FIGURE 4 is a pictorial view of a unitary core structure of the invention bearing separate windings 17 on each core element 12.

With reference to FIGURE 1, the unitary core structure 11 of this invention is seen to comprise a plurality of individual core elements 12 rigidly but separably joined atjoints 14.

The individual. core elements 12 may be made of any suitable or desirable material, and their composition, structure and method of manufacture are not a part of this invention. For example, they may be of wound paper, or of resin-impregnated paper laminates, or of molded plastic, or of compressed and molded paper fibers,

or the like, or of combinations of materials to provide the desired strength and surface characteristics. Their length will be that desired in the final individual wound packages. Their end surfaces 13 should be squarely and cleanly formed with respect to the side surfaces, and relatively smoothly finished to permit good butt joint contact when several of the individual elements 12 are joined together in lengthwise fashion. Thus, the individual elements 12 may be formed individually or by first providing a tubeof any desired economical and convenient length and sawing or otherwise cutting such a tube into the desired lengths of the individual elements 12. The ends 13 of the individual elements may be left absolutely square, or their edges may be lightly rounded or chamfered as at 15 for uses where a smooth edge is desirable, such as over-end unwinding of low-denier, low-twist textile yarns.

The adhesive used in joining the individual elements 12 is characterized by high shear strength and by low tensile strength. A number of adhesives With these characteristics are commercially available and are frequently known as palletizing glues. Adhesives with the necessary characteristics may be based on animal glues; vegetable glues; elastomeric materials, e.g., water emulsions of latex with high solids content; or on numerous synthetic resins, such as polyvinyl alcohols, polyvinyl acetates, copolymers of vinyl acetate and ethylene; and the like. Illustrative of one such composition is that described in U8. Patent No. 3,062,762. he exact materials, composition, and the method of manufacture of the adhesive are not a part of this invention. It should be noted that while there is no critical ratio of shear strength to tensile strength required, the higher ratios are preferred. The objective is to provide sufficient adhesion to prevent separation when adjacent elements have shearing forces applied to their end surfaces while tensile adhesion between adjacent element ends is sufliciently low to permit ready separation with moderate tensile (i.e., perpendicular to the end surface) force application.

In the formation of the unitary core structure 11, any desired number of the individual elements 12 are brought together to form the desired length of final structure. During assembly, the individual elements 12 are held in proper relationship by any convenient means, for example, by sliding over a rod or mandrel. Adhesive of the kind previously described is applied to the end surfaces 13 of the individual elements 12, and the individual elements 12, are then joined in readily understood buttjoined fashion as at 14, to form the unitary structure 11. The specific adhesive selected will determine such factors as the amount of adhesive applied, the curing or setting time required, and whether or not adhesive is applied to one or both surfaces 13 at each joint 14. In some instances, it may be necessary to apply adhesive to the entire end surface 13, of each element 12, but it has been found surprisingly that adequate strength and stability are achieved in many cases and subsequent separation of the components is facilitated when the individual elements 12 are spot glued by applying adhesive in a number of spaced areas or spots 16 around each end surface.

By way of illustration, a number of individual elements 12, each approximately 2.25 inches (5.7 cm.) in length, and of diameter and thickness suitable for a specific winding machine, are made of a wound paper structure of a kind conventionally used for cores for textile yarns. A number of unitary core structures 11, each comprising two of the individual elements 12, are made. The individual elements 12, are joined with a commercially available adhesive identified as Morningstar-Paisley Glue No. 983 and believed to be a natural latex base with synthetic resin additives. An additional number of unitary cores 11, each also comprising two individual elements 12, are made with another commercially available adhesive, identified as Morningstar-Paisley Glue No. 9960 and also believed to be a natural latex base with synthetic resin additives. Both of the adhesives used have the high shear strength and the low tensile strength desired for making ment 12. Each yarn package contains approximately two pounds of textile yarn. Winding is carried out at a speed of 700 yd./min. (640 meters/min), equivalent to a rotational speed of 2470 r.p.m. for the cores. Despite the relatively large yarn package and the high winding speed employed, the unitary core structures 11 remain intact not only in the winding operation but in subsequent handling and shipping. They are found to be readily separable as by breaking at the glue line, for use as independent packages when desired. Equally satisfactory results are obtained for the unitary cores made with the two different adhesives.

While the invention has thus been illustrated in terms of a textile Winding core of a specific kind, it will be understood that the unitary core structure of this invention has wide application wherever it is desired to wind a number of individual packages at one time, the packages being later separable for independent use. Since many specific embodiments may be made without departing from the spirit of the invention, the invention is not intended to be restricted to the embodiment illustrated or to any other specific embodiment, except as defined in the appended claim.

What is claimed is:

A yarn package having separate windings that have been simultaneously wound on each of at least two readily separable cylindrical core elements of a unitary tubular core and are simultaneously unwindable therefrom, said core elements being axially aligned and arranged in abutting end-to-end relationship and rigidly secured in position in the unitary tubular core by means of a latex based adhesive that is located at spaced areas Within the abutting end surface areas of the core elements, said adhesive having high shear strength to enable the unitary tubular core to withstand the mechanical strains of winding at high speeds and low tensile strength so that said unitary tubular core can be readily pulled apart by application of slight tensile force into individual core elements each bearing separate windings for use as single yarn packages, and said core elements having end and central sections, the latter being of uniform radius along its length and constituting the yarn winding support, and each end sec tion having a radius that does not exceed that of the central section to permit over-end yarn take off while avoiding yarn abrasion.

References Cited by the Examiner UNITED sTATEs PATENTS 2,603,348 7/1952 Lippey 20659X 3,044,728 '7/1962 Landgrafetal 242-68.5

3,062,762 11/1962 Rice etal. 26017 3,176,932 4/1965 Kovaleski 242118.41X

FOREIGN PATENTS 588,464 12/1959 Canada.

STANLEY N. GILREATH, Primary Examiner.

FRANK I. COHEN, Examiner.

W. S. BURDEN, Assistant Examiner. 

